Multiple Paternity and Heritability of Color in Drymarchon couperi (Eastern Indigo Snakes)

摘要

Multiple paternity of clutches is common in many vertebrates, including snakes, and understanding how frequently it occurs within a species is important for determining the role it might play in conserving that species. One such species, Drymarchon couperi (Eastern Indigo Snakes), is the subject of an ongoing captive-breeding program and repatriation project in the southeastern United States. Many characteristics of the reproductive biology of this species are poorly understood, including whether clutches are sired by more than one male, and which characteristics, if any, are selected in potential mates. Sexual dichromatism has been suggested to occur in this species and, as such, one characteristic that might play a role in sexual selection is color. Our first objective was to determine if multiple paternity occurs in source and repatriated populations of D. couperi. Second, we examined whether color might play a role in sexual selection or sex identification. Therefore, we also tested hypotheses examining associations between color, heritability, and multiple paternity. We found that multiple paternity likely occurred in ?31% of the clutches. Furthermore, heritability of color was relatively high, but single-sired and multisired clutches were similar in color and in the variability of color within a clutch. We conclude that management of D. couperi could benefit by exposing captive-bred females to multiple males within a mating season. This will allow for use of stored sperm to inseminate eggs after release or for females to seek new mates among the repatriated population.